Gas reservoir development water body multiple determination method, system, equipment and medium

Abstract

The invention provides a gas reservoir development water body multiple determination method, system and equipment and a medium. The method comprises the following steps: determining a dynamic relationship between dynamic reserves and static geological reserves of a completely developed gas reservoir based on a statistical induction method; based on a regression analysis method, the dynamic reserves of the closed complex gas reservoir with the uncertain gas-water interface are obtained; evaluating the static geological reserves of the complex gas reservoir based on the dynamic relationship and the dynamic reserves of the complex gas reservoir; based on static geological reserves and a volume method, the gas-bearing area and the gas-water interface of the gas reservoir are evaluated in a back-stepping mode; based on the gas reservoir gas-bearing area and the gas-water interface, the volume method is adopted to evaluate the water volume; obtaining a water body multiple based on the relationship between the water body volume and the water body multiple; according to the method, the unknown gas-water interface and the water body multiple are reversely deduced and evaluated through the dynamic method, and guidance is provided for water prevention and control of the gas reservoir.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield development, and in particular relates to a method, system, equipment and medium for determining water body multiples in gas reservoir development. Background Art

[0002] In the existing technology, most conventional gas reservoirs belong to water-driven gas reservoirs to varying degrees, and gas reservoirs with active edge and bottom water account for 40% to 50%. During the development of water-driven gas reservoirs, as gas is produced and formation pressure decreases, water gradually invades the gas reservoir. The invasion of water can effectively replenish formation energy on the one hand, and on the other hand, it will increase the abandoned pressure of the gas reservoir and reduce the recovery rate of the gas reservoir. Therefore, the problem of edge and bottom water has always been the focus of oil and gas reservoir engineers. The calculation of water invasion volume, water volume, water multiples and geological reserves of water-driven gas reservoirs is the basis for the rational and efficient development of gas reservoirs, and is of great significance to the adjustment of technical policies for the later development of water-driven gas reservoirs.

[0003] In recent years, scholars have begun to pay attention to the size of water bodies. The driving effect of edge and bottom water on oil and gas and the impact on water content are all related to its size. Therefore, it is very necessary to calculate the volume of edge and bottom water for oil and gas reservoir development. The size of edge and bottom water bodies is often represented by water body multiples, which is the ratio of the volume of edge and bottom water to underground oil and gas. It is aimed at closed and complex gas reservoirs with uncertain gas-water interface. However, the methods used to calculate water body multiples in the existing technology are relatively complicated and difficult to calculate, and the calculation accuracy is poor, and it is impossible to accurately characterize the size of edge and bottom water bodies. Summary of the invention

[0004] In response to the problems existing in the prior art, the present invention provides a method, system, equipment and medium for determining the water body multiple of gas reservoir development. The present application can simultaneously calculate the static geological reserves, gas-water interface and water body volume of the gas reservoir, providing guidance for water prevention and control of the gas reservoir.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for determining the water body multiple of gas reservoir development comprises the following steps:

[0007] Determine the dynamic relationship between dynamic reserves and static geological reserves of fully developed gas reservoirs based on statistical induction;

[0008] Based on the regression analysis method, the dynamic reserves of complex gas reservoirs with closed gas-water interface uncertainty are obtained;

[0009] Evaluate the static geological reserves of complex gas reservoirs based on dynamic relationships and dynamic reserves of complex gas reservoirs;

[0010] Inversely evaluate the gas-bearing area and gas-water interface of gas reservoirs based on static geological reserves and volumetric method;

[0011] The volume of water body is evaluated by volumetric method based on the gas-bearing area of ​​gas reservoir and gas-water interface;

[0012] The water body multiple is obtained based on the relationship between the water body volume and the water body multiple.

[0013] Furthermore, the process of determining the dynamic relationship between the dynamic reserves and the static geological reserves of the fully developed gas reservoir based on the statistical induction method is as follows:

[0014] The gas reservoirs of the same type are classified, and their corresponding dynamic reserves and static geological reserves are established in the same coordinate system. All data points are regressed into a straight line, and the conversion coefficient between the static geological reserves and dynamic reserves of the gas reservoirs is obtained.

[0015] Furthermore, in the process of obtaining the dynamic reserves of a closed complex gas reservoir with uncertain gas-water interface based on the regression analysis method, a linear regression analysis method and a nonlinear regression analysis method are respectively used according to their linear relationship and nonlinear relationship, and the linear regression analysis method includes the following steps:

[0016] For a gas reservoir with natural water drive, when the cumulative production Gp gas volume is put into production, the formation pressure drops to:

[0017] (ΔP = Pi - P);

[0018] At this time, it will cause the expansion of gas in the gas reservoir, the expansion of rock and bound water, and the water invasion of natural waters. The underground cumulative effect of the three is equal to the underground cumulative gas production of the gas reservoir. It is obtained that (P / Z)(1-CeΔP-ω) is linearly related to Gp, and the slope of the straight line segment is The intercept of the straight line segment is

[0019] Based on the deformation of the material balance equation of closed gas reservoir, ((P i / Z i ) / (P / Z)-1) / (Δp) and ((P i / Z i )G p / ΔP(P / Z)) is linear, and the slope of the straight line is The intercept of the straight line is C e , the derivative of the slope of the straight line segment is the dynamic reserve G, and the ratio of the intercept to the slope is the dynamic reserve G;

[0020] Where Δp is the formation pressure drop, MPa; p i is the original formation pressure of the gas reservoir, MPa; p is the formation pressure of the gas reservoir at a certain production time, MPa; P / Z is the apparent formation pressure under the gas reservoir p pressure, MPa; p i is the original formation pressure of the gas reservoir, MPa; G is the dynamic reserves of the gas reservoir, 108m3 ; pi / Zi is gas reservoir p i Apparent formation pressure under pressure, MPa; ω is a water invasion related parameter, C e is the effective compression factor, MPa-1; Z is the gas deviation coefficient under the conditions of p and gas reservoir temperature.

[0021] Furthermore, the nonlinear regression analysis method comprises the following steps:

[0022] The approximate linear relationship of the closed gas reservoir balance equation based on the compressibility factor as a variable:

[0023] C e (p)P i -P≈λGP,

[0024] get

[0025] Based on the pressure, cumulative production data and natural gas deviation coefficient, the binomial regression method is used to determine the parameters.

[0026] The nonlinear regression method was used to determine the parameters: Get G;

[0027] Based on the material balance equation of closed gas reservoir: get If the original pressure, temperature and natural gas properties of the gas reservoir are known, ZD can be calculated, and then a typical curve can be established. Based on actual production data, D —G p Plot a series of data points on a semi-logarithmic graph (G p , P D ), and stack it on P D —G pD On the semi-logarithmic typical curve plate;

[0028] Move the data points up and down to align the ordinate axis, and move the data points left and right to align them with P D —G pD A C in the semi-logarithmic typical curve D The corresponding curve is fitted to determine C D , read the fitting points, and then calculate G and C e ;

[0029] Where Δp is the formation pressure drop, MPa; p i is the original formation pressure of the gas reservoir, MPa; p is the formation pressure of the gas reservoir at a certain production time, MPa; P / Z is the apparent formation pressure under the gas reservoir p pressure, MPa; pi is the original formation pressure of the gas reservoir, MPa; G is the dynamic reserves of the gas reservoir, 108m 3 ; pi / Zi is gas reservoir p i Apparent formation pressure under pressure, MPa; ω is a water invasion related parameter, Ce is the effective compression coefficient, MPa-1; Z is the gas deviation coefficient under the conditions of p and gas reservoir temperature; C D is dimensionless, C D =C e p i ; Z D is dimensionless, G pD is the ratio of cumulative gas production to actual geological reserves,

[0030] Furthermore, the process of evaluating the static geological reserves of a complex gas reservoir based on the dynamic relationship and the dynamic reserves of the complex gas reservoir is as follows:

[0031] According to the evaluated dynamic reserves G of complex gas reservoirs and the reserve conversion coefficient Gz, the static geological reserves Gc of complex gas reservoirs are calculated:

[0032] G c =G×G z =1.0394G.

[0033] Furthermore, the process of inversely evaluating the gas-bearing area and gas-water interface of a gas reservoir based on static geological reserves and volumetric method is as follows:

[0034] For static reserves, the volumetric method is used to calculate the geological reserves of gas reservoirs:

[0035] G c =0.01A g h gi / B gi ;

[0036] The effective thickness h of the gas reservoir is calculated by the well point area trade-off method; the effective porosity Ф of the gas reservoir is calculated by the well point area trade-off method; the gas saturation S gi It is obtained by using the well point area trade-off method;

[0037] Original natural gas volume coefficient B gi Using formula B gi =(P sc ×T×Z i ) / (T sC ×P i );

[0038] The ground standard temperature Tsc is 293.15K (20°C), and the pressure Psc is 0.101MPa. The original gas reservoir formation pressure P is converted by using the measured pressure gradient and temperature gradient of the adjacent area or borrowing the measured pressure gradient and temperature gradient of the adjacent area. i , temperature T; gas deviation coefficient Z i The results of single-well PVT experiment analysis were used;

[0039] The gas-containing area Ag is:

[0040]

[0041] Where, h is the effective thickness, m; Ф is the effective porosity; S gi is the original gas saturation of the gas reservoir; B gi For i Volume coefficient of gas under pressure; G c The geological reserves of the gas reservoir are 108m 3 ; G is the dynamic reserves of gas reservoir, 108m 3 ;

[0042] Based on the gas-bearing area Ag and the gas reservoir structure contour map, the gas-bearing outer boundary elevation, that is, the gas-water interface elevation hw, is inferred.

[0043] Furthermore, the process of evaluating the water volume by using the volumetric method based on the gas-bearing area of ​​the gas reservoir and the gas-water interface is as follows:

[0044] Evaluate the volume of a water body using the volumetric method:

[0045] V w =100A w h wi ;

[0046] V w =100(SA g )hФ;

[0047] Including: Water area A w =SA g (km 2 ); the effective thickness h is obtained by using the effective thickness contour area trade-off method; the effective porosity Φ is obtained by weighting the porosity calculated by well logging and the corresponding effective thickness; the water saturation S wi is 100%;

[0048] The process of obtaining the water body multiple based on the relationship between the water body volume and the water body multiple is:

[0049]

[0050] Where n is the water volume multiple; V w is the volume of water, 104 m 3 ; B gi For i Volume coefficient of gas under pressure; G c The geological reserves of the gas reservoir are 108m 3 .

[0051] A system for determining water body multiples for gas reservoir development, comprising:

[0052] Dynamic relationship module, used to determine the dynamic relationship between dynamic reserves and static geological reserves of fully developed gas reservoirs based on statistical induction;

[0053] Dynamic reserve module, used to obtain dynamic reserves of complex gas reservoirs with closed and uncertain gas-water interface based on regression analysis method;

[0054] Static geological reserves module, used to evaluate the static geological reserves of complex gas reservoirs based on dynamic relationships and dynamic reserves of complex gas reservoirs;

[0055] Evaluation module, used to reversely evaluate the gas-bearing area and gas-water interface of gas reservoirs based on static geological reserves and volumetric method;

[0056] Water volume module, used to evaluate water volume using volumetric method based on gas reservoir gas-bearing area and gas-water interface;

[0057] The water body multiple module is used to obtain the water body multiple based on the relationship between the water body volume and the water body multiple.

[0058] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of a method for determining the water body multiple of gas reservoir development are implemented.

[0059] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a method for determining the water body multiple of gas reservoir development.

[0060] Compared with the prior art, the present invention has the following beneficial technical effects:

[0061] The present invention provides a method, system, equipment and medium for determining the water body multiple of gas reservoir development, comprising the following steps: determining the dynamic relationship between the dynamic reserves and the static geological reserves of a fully developed gas reservoir based on a statistical induction method; obtaining the dynamic reserves of a closed complex gas reservoir with uncertain gas-water interface based on a regression analysis method; evaluating the static geological reserves of a complex gas reservoir based on the dynamic relationship and the dynamic reserves of the complex gas reservoir; evaluating the gas-bearing area and the gas-water interface of the gas reservoir based on the static geological reserves and the volumetric method; evaluating the water body based on the gas-bearing area and the gas-water interface of the gas reservoir using the volumetric method. volume; the water body multiple is obtained based on the relationship between the water body volume and the water body multiple; the present invention is based on the dynamic relationship between the dynamic reserves and the static geological reserves of the fully developed gas reservoir, obtains the conversion coefficient between the static geological reserves and the dynamic reserves of the gas reservoir, calculates the static geological reserves of the complex gas reservoir according to the evaluated dynamic reserves and the conversion coefficient, and then uses the volumetric method to reversely evaluate the gas-water interface and the water body volume, and finally evaluates the water body multiple of the gas reservoir; the present application uses the dynamic method to reversely evaluate the unknown gas-water interface and water body multiple, and provides guidance for water prevention and control of gas reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 A flow chart of a method for determining water body multiples for gas reservoir development according to the present invention;

[0063] Figure 2 A curve diagram showing the relationship between the static geological reserves and the dynamic reserves of a gas reservoir in an embodiment of the present invention;

[0064] Figure 3 It is a schematic diagram of the top surface structure of a complex gas reservoir in an embodiment of the present invention;

[0065] Figure 4 A schematic diagram of another complex gas reservoir top surface structure in an embodiment of the present invention;

[0066] Figure 5 This is a schematic diagram of a closed gas reservoir K plane in a basin in western China according to an embodiment of the present invention;

[0067] Figure 6 This is a dynamic reserve evaluation diagram of the K gas reservoir p / Z material balance method in an embodiment of the present invention;

[0068] Figure 7 This is a dynamic reserve evaluation diagram of the K gas reservoir using a semi-logarithmic nonlinear regression method in an embodiment of the present invention;

[0069] Figure 8 It is a schematic diagram of the K plane of a closed gas reservoir in a basin in western China in an embodiment of the present invention;

[0070] Fig. 9 Schematic diagram of the gas reservoir cross section of K gas reservoir in an embodiment of the present invention. DETAILED DESCRIPTION

[0071] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0072] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0073] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0074] The present invention provides a method for determining the water body multiple of gas reservoir development, such as Figure 1 As shown, the following steps are included:

[0075] Determine the dynamic relationship between dynamic reserves and static geological reserves of fully developed gas reservoirs based on statistical induction;

[0076] Based on the regression analysis method, the dynamic reserves of complex gas reservoirs with closed gas-water interface uncertainty are obtained;

[0077] Evaluate the static geological reserves of complex gas reservoirs based on dynamic relationships and dynamic reserves of complex gas reservoirs;

[0078] Inversely evaluate the gas-bearing area and gas-water interface of gas reservoirs based on static geological reserves and volumetric method;

[0079] The volume of water body is evaluated by volumetric method based on the gas-bearing area of ​​gas reservoir and gas-water interface;

[0080] The water body multiple is obtained based on the relationship between the water body volume and the water body multiple.

[0081] Preferably, the process of determining the dynamic relationship between the dynamic reserves and the static geological reserves of the fully developed gas reservoir based on the statistical induction method is as follows:

[0082] The gas reservoirs of the same type are classified, and their corresponding dynamic reserves and static geological reserves are established in the same coordinate system. All data points are regressed into a straight line, and the conversion coefficient between the static geological reserves and dynamic reserves of the gas reservoirs is obtained.

[0083] Preferably, in the process of obtaining the dynamic reserves of a closed complex gas reservoir with uncertain gas-water interface based on the regression analysis method, a linear regression analysis method and a nonlinear regression analysis method are respectively adopted according to their linear relationship and nonlinear relationship, and the linear regression analysis method comprises the following steps:

[0084] For a gas reservoir with natural water drive, when the cumulative production Gp gas volume is put into production, the formation pressure drops to:

[0085] (ΔP = Pi - P);

[0086] At this time, it will cause the expansion of gas in the gas reservoir, the expansion of rock and bound water, and the water invasion of natural waters. The underground cumulative effect of the three is equal to the underground cumulative gas production of the gas reservoir. It is obtained that (P / Z)(1-CeΔP-ω) is linearly related to Gp, and the slope of the straight line segment is The intercept of the straight line segment is

[0087] Based on the deformation of the material balance equation of closed gas reservoir, ((P i / Z i ) / (P / Z)-1) / (Δp) and ((P i / Z i )G p / ΔP(P / Z)) is linear, and the slope of the straight line is The intercept of the straight line is C e , the derivative of the slope of the straight line segment is the dynamic reserve G, and the ratio of the intercept to the slope is the dynamic reserve G;

[0088] Where Δp is the formation pressure drop, MPa; p i is the original formation pressure of the gas reservoir, MPa; p is the formation pressure of the gas reservoir at a certain production time, MPa; P / Z is the apparent formation pressure under the gas reservoir p pressure, MPa; p i is the original formation pressure of the gas reservoir, MPa; G is the dynamic reserves of the gas reservoir, 108m 3 ; pi / Zi is gas reservoir p i Apparent formation pressure under pressure, MPa; ω is a water invasion related parameter, C e is the effective compression factor, MPa-1; Z is the gas deviation coefficient under the conditions of p and gas reservoir temperature.

[0089] Preferably, the nonlinear regression analysis method comprises the following steps:

[0090] The approximate linear relationship of the closed gas reservoir balance equation based on the compressibility factor as a variable:

[0091] C e (p)P i -P≈λGP,

[0092] get

[0093] Based on the pressure, cumulative production data and natural gas deviation coefficient, the binomial regression method is used to determine the parameters.

[0094] The nonlinear regression method was used to determine the parameters: Get G;

[0095] Based on the material balance equation of closed gas reservoir: get If the original pressure, temperature and natural gas properties of the gas reservoir are known, ZD can be calculated, and then a typical curve can be established. Based on actual production data, D —G p Plot a series of data points on a semi-logarithmic graph (G p , P D ), and stack it on P D —G pD On the semi-logarithmic typical curve plate;

[0096] Move the data points up and down to align the ordinate axis, and move the data points left and right to align them with P D —G pD A C in the semi-logarithmic typical curve D The corresponding curve is fitted to determine C D , read the fitting points, and then calculate G and C e ;

[0097] Where Δp is the formation pressure drop, MPa; p i is the original formation pressure of the gas reservoir, MPa; p is the formation pressure of the gas reservoir at a certain production time, MPa; P / Z is the apparent formation pressure under the gas reservoir p pressure, MPa; p i is the original formation pressure of the gas reservoir, MPa; G is the dynamic reserves of the gas reservoir, 108m 3 ; pi / Zi is gas reservoir p i Apparent formation pressure under pressure, MPa; ω is a water invasion related parameter, Ce is the effective compression coefficient, MPa-1; Z is the gas deviation coefficient under the conditions of p and gas reservoir temperature; CD is dimensionless, C D =C e p i ; Z D is dimensionless, G pD is the ratio of cumulative gas production to actual geological reserves,

[0098] Preferably, the process of evaluating the static geological reserves of a complex gas reservoir based on the dynamic relationship and the dynamic reserves of the complex gas reservoir is:

[0099] According to the evaluated dynamic reserves G of complex gas reservoirs and the reserve conversion coefficient Gz, the static geological reserves Gc of complex gas reservoirs are calculated:

[0100] G c =G×G z =1.0394G.

[0101] Preferably, the process of inversely evaluating the gas-bearing area and gas-water interface of a gas reservoir based on static geological reserves and volumetric method is as follows:

[0102] For static reserves, the volumetric method is used to calculate the geological reserves of gas reservoirs:

[0103] G c =0.01A g h gi / B gi ;

[0104] The effective thickness h of the gas reservoir is calculated by the well point area trade-off method; the effective porosity Ф of the gas reservoir is calculated by the well point area trade-off method; the gas saturation S gi It is obtained by using the well point area trade-off method;

[0105] Original natural gas volume coefficient B gi Using formula B gi =(P sc ×T×Z i ) / (T sc ×P i );

[0106] The ground standard temperature Tsc is 293.15K (20°C), and the pressure Psc is 0.101MPa. The original gas reservoir formation pressure P is converted by using the measured pressure gradient and temperature gradient of the adjacent area or borrowing the measured pressure gradient and temperature gradient of the adjacent area. i , temperature T; gas deviation coefficient Z i The results of single-well PVT experiment analysis were used;

[0107] The gas-containing area Ag is:

[0108]

[0109] Where, h is the effective thickness, m; Ф is the effective porosity; S gi is the original gas saturation of the gas reservoir; B gi For i Volume coefficient of gas under pressure; G c The geological reserves of the gas reservoir are 108m 3 ; G is the dynamic reserves of gas reservoir, 108m 3 ;

[0110] Based on the gas-bearing area Ag and the gas reservoir structure contour map, the gas-bearing outer boundary elevation, that is, the gas-water interface elevation hw, is inferred.

[0111] Preferably, the process of evaluating the water volume by using the volumetric method based on the gas-bearing area of ​​the gas reservoir and the gas-water interface is as follows:

[0112] Evaluate the volume of a water body using the volumetric method:

[0113] V w =100A w h wi ;

[0114] V w =100(SA g )hФ;

[0115] Including: Water area A w =SA g (km 2 ); the effective thickness h is obtained by using the effective thickness contour area trade-off method; the effective porosity Φ is obtained by weighting the porosity calculated by well logging and the corresponding effective thickness; the water saturation S wi is 100%;

[0116] The process of obtaining the water body multiple based on the relationship between the water body volume and the water body multiple is:

[0117]

[0118] Where n is the water volume multiple; V w is the volume of water, 10 4 m 3 ; B gi For i Volume coefficient of gas under pressure; G c The geological reserves of the gas reservoir are 108m 3 .

[0119] The present invention provides an embodiment:

[0120] Step 1: Use statistical induction to determine the dynamic relationship between dynamic reserves and static geological reserves of fully developed gas reservoirs:

[0121] The dynamic reserves and static geological reserves of five gas reservoirs of the same type in the jurisdiction are statistically summarized, as shown in Table 1:

[0122] Table 1 Reserve statistics

[0123]

[0124] Draw a relationship curve between the static geological reserves and dynamic reserves of a gas reservoir in a rectangular coordinate system, such as Figure 2 As shown, the data points regress into a straight line with good correlation.

[0125] According to the regression formula, the conversion coefficient Gz between the static geological reserves and dynamic reserves of the gas reservoir is 1.0394.

[0126] Step 2: Dynamic reserves calculation for closed and complex gas reservoirs with uncertain gas-water interface:

[0127] Calculation method ①: Linear regression analysis

[0128] Pressure drop method: In addition to considering the elastic driving energy of gas, the commonly used pressure drop method also needs to consider the expansion energy of rock and the influence of water invasion. For a gas reservoir with natural water drive, when the cumulative production of Gp gas volume is put into production, the formation pressure drops to (ΔP = Pi-P). At this time, it will cause the expansion of gas in the gas reservoir, the expansion of rock and bound water, and the water invasion of natural waters. The underground cumulative effect of the three is equal to the underground cumulative gas production of the gas reservoir, that is, (P / Z)(1-CeΔP-ω) is linearly related to Gp, and the slope of the straight line segment is The intercept of the straight line segment is The ratio of the intercept to the slope is the dynamic reserve G;

[0129] Roach analysis method. In 1981, Roach transformed the material balance equation of closed gas reservoirs into a linear relationship between ((Pi / Zi) / (P / Z)-1) / (ΔP) and ((Pi / Zi)Gp / ΔP(P / Z)). The slope of the straight line segment is The intercept of the straight line segment is Ce, that is, the derivative of the slope of the straight line segment is the dynamic reserve G. This method is simple and convenient, and can not only calculate the dynamic reserve, but also calculate the effective compression coefficient.

[0130] Calculation method ②: nonlinear regression analysis

[0131] Gonzales binomial method: In 2008, Gonzales proposed an approximate linear relationship Ce(p)Pi-P≈λGP for the closed gas reservoir balance equation with compressibility as a variable (Fetkovich, 1998), that is, Based on the pressure, cumulative production data and natural gas deviation coefficient, the binomial regression method is used to determine the parameters. The nonlinear regression method was used to determine the parameters, namely Then G is calculated.

[0132] Semi-logarithmic nonlinear regression method, Ambastha in 1991 made the closed gas reservoir material balance equation (Bourgoyne, 1972) dimensionless. Right now If the original reservoir pressure, temperature and natural gas properties are known, ZD can be calculated and a typical curve can be established. D —G p Plot a series of data points on a semi-logarithmic graph (G p , P D ), and stack it on P D —G pD On the semi-logarithmic typical curve plate; move the data points up and down to align the ordinate axis, and then move the data points left and right to align them with P D —G pD A C in the semi-logarithmic typical curve D The corresponding curve is fitted to determine C D , read the fitting points, and then calculate G and C e .

[0133] Step 3: Evaluate the static geological reserves of complex gas reservoirs;

[0134] According to the dynamic reserves G of the complex gas reservoir evaluated and the reserve conversion coefficient Gz, the static geological reserves Gc of the complex gas reservoir is calculated, that is:

[0135] G c =G×G z =1.0394G;

[0136] Step 4: Inversely evaluate the gas-bearing area and gas-water interface of the gas reservoir based on the volumetric method;

[0137] The top surface structure of a complex gas reservoir is shown in Figure 2. Figure 3 As shown, the total area is Skm 2 , which is a closed gas reservoir, and the gas-water interface is currently unclear.

[0138] According to the "Petroleum and Natural Gas Reserve Calculation Specification" (DZ / T 0217-2020), the volumetric method is used to calculate the geological reserves of gas reservoirs for static reserves:

[0139] G c =0.01A g h gi / B gi ;

[0140] The effective thickness h of the gas reservoir is calculated by the well point area trade-off method; the effective porosity Ф of the gas reservoir is calculated by the well point area trade-off method; the gas saturation S gi It is obtained by using the well point area trade-off method;

[0141] Original natural gas volume coefficient B gi Using formula B gi =(P sc ×T×Z i ) / (T sc ×P i );

[0142] The ground standard temperature Tsc is 293.15K (20°C), and the pressure Psc is 0.101MPa. The original gas reservoir formation pressure P is converted by using the measured pressure gradient and temperature gradient of the adjacent area or borrowing the measured pressure gradient and temperature gradient of the adjacent area. i , temperature T; gas deviation coefficient Z i The results of single-well PVT experiment analysis were used;

[0143] The gas-containing area Ag is:

[0144]

[0145] Where, h is the effective thickness, m; Ф is the effective porosity; S gi is the original gas saturation of the gas reservoir; B gi For i Volume coefficient of gas under pressure; G c The geological reserves of the gas reservoir are 108m 3 ; G is the dynamic reserves of gas reservoir, 108m 3 ;

[0146] Based on the gas-bearing area Ag and the contour map of the gas reservoir structure, the gas-bearing outer boundary elevation, i.e., the gas-water interface elevation hw, is inferred. Figure 4 shown.

[0147] Step 5: Evaluate the volume of water using the volumetric method:

[0148] V w =100A w h wi ;

[0149] V w =100(SA g )hФ;

[0150] Including: Water area A w =SA g (km 2 ); the effective thickness h is obtained by using the effective thickness contour area trade-off method; the effective porosity Φ is obtained by weighting the porosity calculated by well logging and the corresponding effective thickness; the water saturation S wi is 100%.

[0151] Step 6: Evaluate the water volume multiple of the gas reservoir:

[0152]

[0153] Among them, G is the dynamic reserves of the gas reservoir, 108m3; Gc is the geological reserves of the gas reservoir, 108m3; Gz is the reserve conversion coefficient; Gp is ​​the cumulative gas production, 104m3; pi is the original formation pressure of the gas reservoir, MPa; p is the formation pressure of the gas reservoir at a certain production time, MPa; Δp is the formation pressure drop, MPa; Ce is the effective compression coefficient, MPa-1; pi / Zi is the apparent formation pressure at the pi pressure of the gas reservoir, MPa; P / Z is the apparent formation pressure at the p pressure of the gas reservoir, MPa; ω is a water invasion related parameter, Zi is the gas deviation coefficient under the conditions of pi and gas reservoir temperature; Z is the gas deviation coefficient under the conditions of p and gas reservoir temperature; P D is the dimensionless apparent formation pressure, C D is dimensionless, C D =C e p i ZD is dimensionless, GpD is the ratio of cumulative gas production to actual geological reserves. S is the gas reservoir area, km 2 ; Ag is the gas-bearing area of ​​the gas reservoir, km 2 ; h is effective thickness, m; Ф is effective porosity; Sgi is the original gas saturation of the gas reservoir; Bgi is the volume coefficient of gas at pi pressure; Vw is the water volume, 10 4 m 3 ; Aw is the water area, km 2 ; n is the water volume multiple.

[0154] Embodiment 1:

[0155] An ultra-deep and ultra-high pressure water-sealed gas reservoir K in a basin in western China, Figure 5 As shown, the total area is 40.88km 2The structure is an east-west short-axis anticline. Seven wells have been drilled along the long axis of the structure without encountering any water layer. All wells have been tested and put into production. The reservoir is the Cretaceous Bashikiqik Formation. The effective thickness of the reservoir is 84.67m, the effective porosity is 6%, the gas saturation is 65%, the original formation pressure is 109.17MPa, the pressure coefficient is 1.7, the original natural gas volume coefficient is 0.00229, and the rock compression coefficient is 0.001MPa. -1 , the formation water compressibility coefficient is 0.0004MPa -1 , the formation water volume coefficient is 1.0.

[0156] Table 2. Table of parameters related to dynamic reserve evaluation of K gas reservoir

[0157] years Formation pressure / MPa Coefficient of variation <![CDATA[Cumulative gas production / 10 8 m 3 > <![CDATA[Compressibility factor of natural gas / MPa -1 > 2009 109.17 1.744 0.00 0.00184 2016 108.88 1.741 0.49 0.00192 2017 106.60 1.718 8.05 0.00255 2018 105.02 1.703 11.89 0.00301 2019 100.08 1.654 22.66 0.00448 2020 95.61 1.612 32.34 0.00581 2021 87.40 1.537 44.18 0.00813

[0158] Evaluate the dynamic reserves of K gas reservoir based on historical production data and formation pressure change trends

[0159] The common pressure drop method, Roach analysis method, Gonzales binomial method, semi-logarithmic nonlinear regression method and multi-well RTA method were used to evaluate the dynamic reserves of K gas reservoir. The curve drawn by Roach analysis method has no linear relationship and cannot calculate the dynamic reserves; the calculation result by Gonzales binomial method is too small and does not match the actual production that the current formation pressure drops by 21.77MPa and the cumulative gas production has reached 4.4 billion cubic meters.

[0160] Table 3 K gas reservoir dynamic reserves calculation results

[0161]

[0162] Figure 6 The K gas reservoir p / Z(1-CeΔp) and G are plotted based on the known rock and formation water compressibility and natural gas deviation coefficient. p It is a linear relationship, and the ratio of the intercept of the straight line segment to the slope of the straight line segment is the dynamic reserves of the K gas reservoir, 34.8 billion cubic meters; Figure 7 The semi-logarithmic nonlinear regression is used to draw the K gas reservoir P according to the known gas reservoir formation pressure and natural gas deviation coefficient. D —G p Semi-logarithmic curve and P D —G pD Two plates of semi-logarithmic typical curve, superimpose the two plates, read the fitting points to determine G p G under these conditions pD, and then the dynamic reserves of K gas reservoir were calculated to be 37.8 billion cubic meters; the most typical Blasingame production decline analysis curve was used in the multi-well RTA analysis method to fit and evaluate the dynamic reserves of K gas reservoir to be 39.9 billion cubic meters, and finally the arithmetic average was used to determine the dynamic reserves of K gas reservoir to be 37.5 billion cubic meters.

[0163] According to the dynamic reserves G of gas reservoir K and the reserve conversion coefficient Gz, the static geological reserves Gc of gas reservoir K is calculated, namely:

[0164] G c =G×G z =1.0394G=1.0394×375=389.8×10 8 m 3

[0165] Based on the volumetric method, the gas-bearing area Ag and the gas-water interface hw of the K gas reservoir are inversely evaluated.

[0166] According to the calculated static geological reserves of K gas reservoir of 38.98 billion cubic meters, the gas-bearing area Ag of K gas reservoir is inferred by volumetric method:

[0167]

[0168] According to the calculated gas-bearing area Ag and the gas reservoir structural contour map, it is inferred that the gas-bearing outer boundary elevation of the K gas reservoir is -5036 m, that is, the gas-water interface elevation hw is -4936 m. Figure 8 As shown:

[0169] The volumetric method is used to evaluate the water volume of K gas reservoir:

[0170] V w =100A w h wi

[0171] That is V w =100(SA g )hФ=100×(40.88-27.03)×97.37×0.05=6742.87×10 4 m 3

[0172] Evaluate the water body multiple of K gas reservoir, such as Fig. 9 As shown:

[0173]

[0174] The present invention provides a system for determining the water body multiple of gas reservoir development, comprising:

[0175] Dynamic relationship module, used to determine the dynamic relationship between dynamic reserves and static geological reserves of fully developed gas reservoirs based on statistical induction;

[0176] Dynamic reserve module, used to obtain dynamic reserves of complex gas reservoirs with closed and uncertain gas-water interface based on regression analysis method;

[0177] Static geological reserves module, used to evaluate the static geological reserves of complex gas reservoirs based on dynamic relationships and dynamic reserves of complex gas reservoirs;

[0178] Evaluation module, used to reversely evaluate the gas-bearing area and gas-water interface of gas reservoirs based on static geological reserves and volumetric method;

[0179] Water volume module, used to evaluate water volume using volumetric method based on gas reservoir gas-bearing area and gas-water interface;

[0180] The water body multiple module is used to obtain the water body multiple based on the relationship between the water body volume and the water body multiple.

[0181] In another embodiment of the present invention, a computer device is provided, the computer device includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of a method for determining the water body multiple of gas reservoir development.

[0182] In another embodiment of the present invention, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both built-in storage media in the computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the method for determining the water body multiple of a gas reservoir development in the above embodiment.

[0183] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0184] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0185] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0186] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0187] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining the water body multiple of gas reservoir development, characterized in that: The following steps are involved: Determine the dynamic relationship between dynamic reserves and static geological reserves of fully developed gas reservoirs based on statistical induction; Based on the regression analysis method, the dynamic reserves of complex gas reservoirs with closed gas-water interface uncertainty are obtained; Evaluate the static geological reserves of complex gas reservoirs based on dynamic relationships and dynamic reserves of complex gas reservoirs; Inversely evaluate the gas-bearing area and gas-water interface of gas reservoirs based on static geological reserves and volumetric method; The volume of water body is evaluated by volumetric method based on the gas-bearing area of ​​gas reservoir and gas-water interface; The water body multiple is obtained based on the relationship between the water body volume and the water body multiple.

2. A method for determining the water body multiple of gas reservoir development according to claim 1, characterized in that: The process of determining the dynamic relationship between the dynamic reserves and the static geological reserves of the fully developed gas reservoir based on the statistical induction method is as follows: The gas reservoirs of the same type are classified, and their corresponding dynamic reserves and static geological reserves are established in the same coordinate system. All data points are regressed into a straight line, and the conversion coefficient between the static geological reserves and dynamic reserves of the gas reservoirs is obtained.

3. The method for determining the water body multiple of gas reservoir development according to claim 1, characterized in that: In the process of obtaining the dynamic reserves of a closed complex gas reservoir with uncertain gas-water interface based on the regression analysis method, a linear regression analysis method and a nonlinear regression analysis method are respectively used according to their linear relationship and nonlinear relationship. The linear regression analysis method includes the following steps: For a gas reservoir with natural water drive, when the cumulative production Gp gas volume is put into production, the formation pressure drops to: (ΔP = Pi - P); At this time, it will cause the expansion of gas in the gas reservoir, the expansion of rock and bound water, and the water invasion of natural waters. The underground cumulative effect of the three is equal to the underground cumulative gas production of the gas reservoir. It is obtained that (P / Z)(1-CeΔP-ω) is linearly related to Gp, and the slope of the straight line segment is The intercept of the straight line segment is Based on the deformation of the material balance equation of closed gas reservoir, ((P i / Z i ) / (P / Z)-1) / (Δp) and ((P i / Z i )G p / ΔP(P / Z)) is linear, and the slope of the straight line is The intercept of the straight line is C e , the derivative of the slope of the straight line segment is the dynamic reserve G, and the ratio of the intercept to the slope is the dynamic reserve G; Where Δp is the formation pressure drop, MPa; p i is the original formation pressure of the gas reservoir, MPa; p is the formation pressure of the gas reservoir at a certain production time, MPa; P / Z is the apparent formation pressure under the gas reservoir p pressure, MPa; p i is the original formation pressure of the gas reservoir, MPa; G is the dynamic reserves of the gas reservoir, 108m 3 ; pi / Zi is gas reservoir p i Apparent formation pressure under pressure, MPa; ω is a water invasion related parameter, C e is the effective compression factor, MPa-1; Z is the gas deviation coefficient under the conditions of p and gas reservoir temperature.

4. A method for determining the water body multiple of gas reservoir development according to claim 3, characterized in that: The nonlinear regression analysis method comprises the following steps: The approximate linear relationship of the closed gas reservoir balance equation based on the compressibility factor as a variable: C e (p)P i -P≈λGP, get Based on the pressure, cumulative production data and natural gas deviation coefficient, the binomial regression method is used to determine the parameters. The nonlinear regression method was used to determine the parameters: Get G; Based on the material balance equation of closed gas reservoir: get If the original pressure, temperature and natural gas properties of the gas reservoir are known, ZD can be calculated, and then a typical curve can be established. Based on actual production data, D —G p Plot a series of data points on a semi-logarithmic graph (G p , P D ), and stack it on P D —G pD On the semi-logarithmic typical curve plate; Move the data points up and down to align the ordinate axis, and move the data points left and right to align them with P D —G pD A C in the semi-logarithmic typical curve D The corresponding curve is fitted to determine C D , read the fitting points, and then calculate G and C e ; Where Δp is the formation pressure drop, MPa; p i is the original formation pressure of the gas reservoir, MPa; p is the formation pressure of the gas reservoir at a certain production time, MPa; P / Z is the apparent formation pressure under the gas reservoir p pressure, MPa; p i is the original formation pressure of the gas reservoir, MPa; G is the dynamic reserves of the gas reservoir, 108m 3 ; pi / Zi is gas reservoir p i Apparent formation pressure under pressure, MPa; ω is a water invasion related parameter, Ce is the effective compression coefficient, MPa-1; Z is the gas deviation coefficient under the conditions of p and gas reservoir temperature; C D is dimensionless, C D =C e p i ; Z D is dimensionless, G pD is the ratio of cumulative gas production to actual geological reserves, 5. A method for determining the water body multiple of gas reservoir development according to claim 1, characterized in that: The process of evaluating the static geological reserves of complex gas reservoirs based on the dynamic relationship and the dynamic reserves of complex gas reservoirs is as follows: According to the evaluated dynamic reserves G of complex gas reservoirs and the reserve conversion coefficient Gz, the static geological reserves Gc of complex gas reservoirs are calculated: G c =G×G z =1.0394G。 6. A method for determining the water body multiple of gas reservoir development according to claim 1, characterized in that: The process of inversely evaluating the gas-bearing area and gas-water interface of a gas reservoir based on static geological reserves and volumetric method is as follows: For static reserves, the volumetric method is used to calculate the geological reserves of gas reservoirs: G c =0.01A g hΦS gi / B gi ; The effective thickness h of the gas reservoir is calculated by the well point area trade-off method; the effective porosity Ф of the gas reservoir is calculated by the well point area trade-off method; the gas saturation S gi It is obtained by using the well point area trade-off method; Original natural gas volume coefficient B gi Using formula B gi =(P sc ×T×Z i ) / (T sc ×P i ); The ground standard temperature Tsc is 293.15K (20°C), and the pressure Psc is 0.101MPa. The original gas reservoir formation pressure P is converted by using the measured pressure gradient and temperature gradient of the adjacent area or borrowing the measured pressure gradient and temperature gradient of the adjacent area. i , temperature T; gas deviation coefficient Z i The results of single-well PVT experiment analysis were used; The gas-containing area Ag is: Where, h is the effective thickness, m; Ф is the effective porosity; S gi is the original gas saturation of the gas reservoir; B gi For i Volume coefficient of gas under pressure; G c The geological reserves of the gas reservoir are 108m 3 ; G is the dynamic reserves of gas reservoir, 108m 3 ; Based on the gas-bearing area Ag and the gas reservoir structure contour map, the gas-bearing outer boundary elevation, that is, the gas-water interface elevation hw, is inferred.

7. A method for determining the water body multiple of gas reservoir development according to claim 1, characterized in that: The process of evaluating the water volume by using the volumetric method based on the gas-bearing area of ​​the gas reservoir and the gas-water interface is as follows: Evaluate the volume of a water body using the volumetric method: V w =100A w hФS wi ; V w =100(S-A g )hФ; Including: Water area A w =SA g (km 2 ); the effective thickness h is obtained by using the effective thickness contour area trade-off method; the effective porosity Φ is obtained by weighting the porosity calculated by well logging and the corresponding effective thickness; the water saturation S wi is 100%; The process of obtaining the water body multiple based on the relationship between the water body volume and the water body multiple is: Where n is the water volume multiple; V w is the volume of water, 10 4 m 3 ; B gi For i Volume coefficient of gas under pressure; G c The geological reserves of the gas reservoir are 108m 3 .

8. A system for determining the water body multiple of gas reservoir development, characterized in that: A method for determining the water body multiple for gas reservoir development based on any one of claims 1 to 7, comprising: Dynamic relationship module, used to determine the dynamic relationship between dynamic reserves and static geological reserves of fully developed gas reservoirs based on statistical induction; Dynamic reserve module, used to obtain dynamic reserves of complex gas reservoirs with closed and uncertain gas-water interface based on regression analysis method; Static geological reserves module, used to evaluate the static geological reserves of complex gas reservoirs based on dynamic relationships and dynamic reserves of complex gas reservoirs; Evaluation module, used to reversely evaluate the gas-bearing area and gas-water interface of gas reservoirs based on static geological reserves and volumetric method; Water volume module, used to evaluate water volume using volumetric method based on gas reservoir gas-bearing area and gas-water interface; The water body multiple module is used to obtain the water body multiple based on the relationship between the water body volume and the water body multiple.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of a method for determining the water body multiple for gas reservoir development as described in any one of claims 1-7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of a method for determining the water volume multiple for gas reservoir development as described in any one of claims 1 to 7 are implemented.

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